AI Insight
This is an Expression of Concern regarding a clinical trial published in The Lancet that investigated exenatide once weekly as a potential disease-modifying treatment for Parkinson's disease. Following a regulatory inspection at King's College Hospital NHS Foundation Trust, one of the trial sites, significant problems were identified with trial conduct, oversight, and governance. The inspection revealed critical and major deficiencies that have called into question the reliability of the study's findings.
Why it matters
This concerns a high-profile trial testing whether exenatide, a diabetes medication, could modify the progression of Parkinson's disease, which would represent a major therapeutic advance if valid. The identified regulatory violations mean that treatment decisions and future research directions based on this study should be reconsidered until the issues are resolved.
On Feb 4, 2025, The Lancet published an Article by Nirosen Vijiaratnam and colleagues,1 which reported the efficacy and safety of exenatide once weekly as a potential disease-modifying treatment for people with Parkinson’s disease in the UK.1 On May 18, 2026, The Lancet was made aware of the findings from a regulatory inspection at King’s College Hospital NHS Foundation Trust, one of the clinical trial sites involved in this study, by the corresponding author of the trial. The inspection formed part of a broader review and identified department-wide concerns relating to trial conduct, oversight, and governance, including findings classified by regulators as critical and major.